An experimenter collected data on how well a study guide improved grades on an exam taken late in the semester compared to an exam taken early in the semester. Using a related sample means t test, the results showed that later grades were higher than early grades ( t (74) = 3.64, p
A) The design controlled for students who did poorly both times.
B) The design controlled for extraneous variables like intelligence levels.
C) The design controlled for carry-over effects from already having taken one exam when the second exam was administered.
D) All of the above are advantages of this design.

Question

Quizplus · Accepted Answer

The design controlled for carry-over effects from already having taken one exam when the second exam was administered. This means that the results are more likely to be due to the study guide and not just the fact that students had already taken one exam and were therefore more familiar with the format and content. The other options were not specifically controlled for in this design.

An Experimenter Collected Data on How Well a Study Guide